Aryloxy and arylmercapto - n-methoxyethylacetamidomonothio and dithio phosphates and phosphonates



3,520,956 ARYLOXY AND ARYLMERCAPTO N-METHOXY- ETHYLACETAMIDOMONOTHIO ANDDITIHO PHOSPHATES AND PHOSPHONATES Llewellyn W. Fancher, Orinda, andReed A. Gray, Saratoga, Califi, assignors to Stautier Chemical Company,New York, N.Y., a corporation of Delaware No Drawing.Continuation-impart of application Ser. No. 463,322, June 11, 1965. Thisapplication Oct. 20, 1967, Ser. No. 676,698

Int. Cl. C07f 9/16, 9/30; A01n 9/36 US. Cl. 260944 Claims ABSTRACT OFTHE DISCLOSURE Compounds corresponding to the formula X RArYCHziiNHCHzOHzOOHgSi in which X and Y are, independently, oxygen orsulfur, Ar is phenyl, nuclear chlorinated-phenyl, or naphthyl groups,the chlorination is from 1 to 5 chlorine atoms, inclusive, R is loweralkyl or lower alkoxy and R is lower alkyl. The naphthyl nuclei arebonded through either the a or p nuclear carbon atom. The abovecompounds are effective herbicides, particularly for the control ofgrasses and broadleaf plants with both preemergence and post-emergenceactivity. Representative compounds are:2,4-dichlorophenoxy-N-methoxyethylacetamido-0,0-dimethylphosphorodithioate,2,4,5-trichlorophenoxy-N methoxyethylacetamido 0,0diethylphosphorodithioate, phenoxy-N-methoxyethylacetamido-0,0- diisopropylphosphorodithioate, p chlorophenoxy N-methoxyethylacetamido-0,0-diethylphosphorothioate, pchlorophenylmercaptoN methoxyethylacetamido-0,0- diethylphosphorodithioate,fi-naphthylmercapto-N-methylethylacetamido 0,0 diethylphosphorothioate,2,4-dichlorophonoxy N methoxyethylacetamido O ethyl O npropylphosphorodithioate, and 2,4-dichlorophe noxy Nmethoxyethylacetamido O i propylethylphosphonodithioate.

This application is a continuation-in-part of copending application Ser.No. 463,322, filed June 11, 1965 now abandoned.

This invention relates to certain new and novel phosphorus containingorganic compounds which may be used as eifective herbicides. Morespecifically, this invention relates to certain substituted aryloxyandarylmercaptoacetamido-N-methoxyethylmonothio and dithiophosphates and topreparation and utility of said organophosphorus compounds in herbicidalcompositions.

The compounds comprising the instant class of compounds correspond tothe general formula 0 X R II II/ ArYCHzCNHCHzCHzOCHzSP wherein X and Yare selected from the group consisting of oxygen and sulfur, Ar isselected from the group consisting of phenyl, nuclearchlorinated-phenyl, and naphthyl groups, wherein said chlorination isfrom 1 to 5 chlorine atoms, inclusive, R is lower alkyl or lower alkoxyand R is lower alkyl. Said naphthyl nuclei are bonded through either thea or ,8 nuclear carbon atom.

As employed in this specification the terms lower alkyl and lower alkoxypreferably include those members of the groups containing from 1 to 6carbon atoms, inclu- United States Patent 0 ice sive, in either astraight chain or a branched chain configuration, for example, methyl,ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-amyl, isoamyl,n-hexyl, and Z-ethylbutyl; methoxy, ethoxy, n-propoxy, iso-propoxy,n-butoxy, sec-butoxy, n-amoxy, isoamoxy, n-hexyloxy and isohexyloxy.

It is also possible that other nuclearly substituted phenyl and naphthylcompounds would be operable within the embodiments of the presentinvention. Said substituents can be selected from the group consistingof the halogens, hydroxyl, nitro, alkoxy and alkyl groups and variouscombinations thereof. The method of preparation for the compounds wouldbe substantially the same involving the appropriate substituted-phenoxyacetamide.

The compounds herein contemplated are prepared by various methods. Thegeneral method applied in preparing the compounds is first the reactionof the appropriate dialkyl dithioor monothio phosphoric or phosphonicacid and 37 percent Formalin. This was followed by the condensation ofthe product thus obtained with the appropriate N-B-hydroxyethyl-aryloxyor arylmercaptoacetamide in the presence of a stable acid condensationcatalyst, such as Z-naphthalene sulfonic acid monohydrate. The reactionproceeds readily in the liquid phase. The incorpo ration of an organicsolvent is also useful, facilitating processing as well as agitation ofthe reactants. Temperatures that permit operation in the liquid phaseand which are between room temperature and the reflux temperature of thesolvent, if any is employed, are operable. Preferably the condensationreaction is carried out at reflux temperature, usually at an elevatedtemperature.

It has been found that the compounds of the present invention areparticularly effective as herbicides. They are effective in the controlof grasses and broadleaf plants with both pre-emergence andpost-emergence activity.

The compounds of the present invention are prepared in accordance withthe following typical example.

EXAMPLE Preparation of2,4-dichlorophenoxy-N-methoxyethylacetamido-0,0-dimethylphosphorodithioateThis example is representative of the preparation of aryloxyandarylmercapto-aceta1nido N methoxyethyl derivatives ofdialkyl-substituted monothio and dithiophosphoric acid Within theembodiment of the present invention.

To 20.6 g. (0.13 M) of dimethyldithiophosphoric acid was added withcooling below 15 C., 11.0 cc. (0.14 M) of 37 percent Formalin. Themixture was transferred to a separatory funnel in which had been placed10 cc. of saturated aqueous sodium chloride and cc. of benzene. Afterthorough mixing, the layers were allowed to separate and the bottomaqueous layer reextracted with 50 cc. of benzene. The benzeneextractions were combined, dried over anhydrous magnesium sulfate andfiltered.

The benzene solution of hydroxymethyl-0,0-dimethylphosphorodithioate wasplaced in a reaction flask equipped with a continuous water extractor.To the reaction flask was added 26.4 g. (0.1 M) of N-fl-hydroxyethyl-ZA-dichlorophenoxyacetamide and 1.0 g. of 2-naphthalene sulfonic acidmonohydrate. The mixture was stirred and refluxed until no further waterwas collected in the water trap; this required about 2 hours. Aftercooling, the reaction mixture was washed several times with water, driedover anhydrous magnesium sulfate, filtered and the henzene removed on asteam bath. There was obtained 40.5 g. (93% of theory) of the titlecompound, a viscous liquid, n =1.5753.

The following is a table of the compounds prepared according to theaforedescribed procedure. Compound numbers have been assigned to eachcompound and are used for identification throughout the balance of theapplication.

'('L.), Coss.) and curly dock (Rumex crispus, (L.)) were planted inindividual rows one-half inch deep in Santa Cruz sandy loam soilcontained in compressed paper flats TABLE I X R 8%" x 6 /2" WhlCh are 25 deep. Enough seeds were AI-YOHEPJNHQHZCHZOCH2SIJI/ 5 plantedto giveabout thirty to fifty plants of each of the Weed species ,ineach flat.The flats were watered Com after planting. The spraying solutionisprepared by dis- M X Y R R1 n m solving 50 mg. of the test compound in 3ml. of a solvent,

such as acetone containing 1% Tween 20 (polyoxy- 1 2,4-(lichlorophenyl SO OCHa CH3 1.5753 2 2,4-dichl0rophenyl s 0 OC HEI 021% 1 570gethylenesorbitan mono-laurate) and dllll'tlng with a small 0 0-0 '-c1.554 1 1 i: ii ifiiii i giiifigi S 0 0 011 3 7 i-CZH; 1, 5686 7 amountof water. The following day each flat was sprayed g- 2 8 88 E 85 1: 2%?at the rate of 20 pounds of the candidate compound un- 1 5-" if gigg ggffi g 8 83%? 6%? der test In 80 gallons of solution per acre. Anatomlzer 9:: I 411010 henl s o o-i-o3 1 i-C 1 1:5640 10 gg g g S O i1,5489 was used to spray the solution on the S011 surface. The 11 ph nylS 0 0OH3 CH3 1. 5690 flats wereplaced in a greenhouse at 80 F. andwatered 12 phenyl S O 0C2H5 02135 1.5570

13 phenyl s o g t-( 3 3111 1 0 11, 1. 5419 regularly. Two weeks laterthe degree of weed control was h o a 1. 5403 E1111 gfilfigfi gg g 8 0 22 @2115 5575 determined by comparing the amount of ger minatlon and s giggfilyolrophenyl 8 88 8 {2353 growth of each weed in the treated flatswith weeds in i2 g 8 82 5 56 3i gggg several untreated control flats.The results of this test 20 B-naphtyl s o 00H; i-CaH 1.5888 21-.a-naphthy1 s 0 00113 CH 1. 6246 are reported Table H 22 a-naphtyl s 00i-03H1 i-C3H7 1. 5997 23 a-naphtyl s 0 OCH?! 1-0 11, 1.6115 24p-ehlorophenyl S S 002 5 C2H5 1.5863 25 p-ehlorophenyl S S OCHs CH3 1.6043 26 p-ehlorophenyl O S OC2 s CzHa 1.5539 27 p-ehlorophenyl S SOi-CaH i-C H 1.5596 28 phenyl O S 0C2H5 02H 1. 5460 B-naphthyl O S002115 021515 1.5978 30 2,4-dichlorophenyl S 0 00211 n-C3H1 1.5638 312,4-dichlorophenyl S O C2H5 i-C H 1 5718 1 Compound N0. 1 prepared inthe example.

TABLE II.PREEMERGENCE ACTIVITY RATE 20 LBSJACRE Foxtail or CompoundCrabannual Water- Wild oat Pig- Curly Number grass bluegrass grass orred oat weed Mustard dock f l I:II:I1: 11 1 P F F IIIII +=Slight injury.Moderate injury. Severe injury or death.

As previously mentioned, the herein described novel compositionsproduced in the above described manner are phyto-toxic compounds whichare useful and valuable in controlling various plant species. Thecompounds of this invention were tested as herbicides in the followingmanner.

Pre-ernergence herbicide test Post-emergence herbicide test.

The seeds of five weed species, crabgrass (Digitaria sanguinatis-(L)Scot), watergrass (Echinochloa crusgalli (L.) Beauv.), red oats (Avenasativa, (L.)) or wild oats (Avena faz ua, (L.)), curly dock (Rumexcrispus, (L.)), mustard (Borassica juncea (L.) Coss.) and one crop,pinto beans (Phaseolus vulgaris) were planted in individual rows asdescribed in the pie-emergence test, supra. Two weeks after planting theplant foliage was sprayed with a 0.5% solution of the test compounds ata rate equivalent to 12.5 pounds/ acre. The treated plants were placedback in the greenhouse. Injury ratings were recorded 14 days aftertreatment. The rating system is the same as that used in thepre-ernergence test. Table III lists the results obtained therefrom.

TABLE III Compound Crab- Water- Red oats or Curly Pinto 0. grass grasswild oats dock Mustard beans Slight injury.

++=Moderate injury.

+++=Severe injury or death.

() Control on Velvet-leaf (Abutilon theophmsti, Medic.).

The new compounds of the present invention are used as pre-emergence orpost-emergence herbicides and are applied in a variety of ways atvarious concentrations. In practice the compounds are formulated with aninert carrier, utilizing methods well-known to those skilled in the art,thereby making them suitable for application as dusts, sprays, ordrenches and the like in the form and manner required. The mixtures canbe dispersed in water with the aid of a wetting agent or they can beemployed in organic liquid compositions, oil and water, Water in oilemulsions, with or without the addition of wetting, dispersing remulsifying agents. The amount applied depends upon the nature of theseeds or plants to be controlled and the rate of application varies from1 to approximately 50 pounds per acre. One particularly advantageous wayof applying the compound is a narrow band along a row crop straddlingthe row. In practice the compounds are formulated with an inert carrierutilizing methods well-known to those skilled in the art, thereby makingthem suitable for particular application.

The concentration of a compound of the present invention, constitutingan effective amount in best mode of administration in the utilitydisclosed is readily determinable by those skilled in the art. Variouschanges and modifications are possible without departing from the spiritand scope of the claims.

Ii II ArYCHzCNHCHzCHzOOHzSP wherein X and Y are selected from the groupconsisting of oxygen and sulfur, R is selected from the group consistingof lower alkyl and lower alkoxy, R is lower alkyl, and Ar is a memberselected from the group consisting of phenyl, naphthyl and nuclearchlorinated-phenyl groups, wherein said nuclear chlorination is from 1to 5 chlorine atoms, inclusive.

2. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is methoxy, R is methyl and Ar is 2,4-dichlorophenyl.

3. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is ethoxy, R is ethyl and Ar is 2,4,5-trichl0rophenyl.

4. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is isopropoxy, R is isopropyl and Ar is phenyl.

5. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is ethoxy, R is ethyl and Ar is p-chlorophenyl.

6. The compound according to claim 1 in which X is sulfur, Y is sulfur,R is ethoxy, R is ethyl, and Ar is p-chlorophenyl.

7. The compound according to claim 1 in Which X is sulfur, Y is sulfur,R is ethoxy, R is ethyl and Ar is fi-naphthyl.

8. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is methoxy, R is n-propyl and Ar is 2,4 dichlorophenyl.

9. The compound according to claim 1 in which X is sulfur, Y is oxygen,R is ethyl, R is isopropyl and Ar is 2,4-dichlorophenyl.

References Cited UNITED STATES PATENTS 3,382,300 5/1968 Uchiyama et al260944 CHARLES B. PARKER, Primary Examiner A. H. SUTTO, AssistantExaminer U.S. C1. X.R.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,520 ,956 D t d July 2.1, 1970 'In Lleweliyn W. Fancher et a1.

It 1e certified that error appears in the above-identified patent andthat said Letters Patent: are hereby corrected as shown below:

Column 3, Table 1, Compound No. 9 under Column 3, "0 -i-C H should be 0CH and under Column L "I-C H should be --C H Column 3, Table 1, Com oundNo. 17 26 angL22- 23 under Column 1; the word "naphtyl' shouldbe--'-=naphthy1- smrezn'm swan 00T201970 (SEAL) Attest: 3 Edward M.mmlmh commissioner of magma Mating Offioot

